So far I've rejected Cinema, the V and A (shut) Churchill war rooms (shut), docklands miseum (shut), there's no tickets for the National gallery earlier than 3.45. No shows obvs.
All I've come up with is going to look at the carriages in the Royal Mews (Buckingham palace state rooms are shut so this is the only bit open) plus wandering about 
Anyone know of anything else that's open?
I was in town last week and it was really quiet but I was going to work so not looking for something to 'do'.